Data Science & FP&A

AI Sales Forecasting & Budgeting

Facebook Prophet time-series model predicting demand with 88% accuracy, enabling precise inventory and cash flow planning.

🎯 Business Challenge

Finance team relied on static annual budgets that ignored seasonality, leading to:

  • Inventory Mismatches: Overstocked in slow months, stockouts in peak season.
  • Cash Flow Surprises: Unexpected shortfalls because demand wasn't accurately predicted.
  • Manual Forecasting: Analysts spending 2 weeks each quarter adjusting Excel spreadsheets.

💡 Solution: Facebook Prophet Model

Implemented Prophet (developed by Meta) for time-series forecasting, capturing seasonality, trends, and holidays automatically.

Implementation

from prophet import Prophet
import pandas as pd

# Prepare data (Prophet requires 'ds' and 'y' columns)
df = pd.read_csv('sales_history.csv')
df = df.rename(columns={'date': 'ds', 'sales': 'y'})

# Train model
model = Prophet(
    yearly_seasonality=True,
    weekly_seasonality=True,
    daily_seasonality=False,
    holidays=holidays_df  # Black Friday, Christmas, etc.
)
model.fit(df)

# Generate 6-month forecast
future = model.make_future_dataframe(periods=180)
forecast = model.predict(future)

# Visualize
model.plot(forecast)
model.plot_components(forecast)  # Trend, seasonality breakdown

📈 Key Results

  • 88% MAPE Accuracy: Mean Absolute Percentage Error of 12% (industry benchmark: 20%).
  • Inventory Optimization: Reduced holding costs by 18% through better demand planning.
  • Cash Flow Precision: Forecasted revenue within 5% accuracy enabled better working capital management.
  • Time Savings: 2 weeks → 2 hours for quarterly forecast updates.

🛠️ Model Features

  • Seasonality Detection: Automatically captured weekly, monthly, yearly patterns.
  • Holiday Effects: Modeled Black Friday, Christmas spikes without manual rules.
  • Confidence Intervals: Provided upper/lower bounds for risk planning.
  • Power BI Integration: Forecasts visualized in executive dashboards.

🚀 Future Enhancements

  • Multi-SKU Forecasting: Separate models for each product category.
  • External Regressors: Incorporate marketing spend, competitor pricing.
  • Real-Time Updates: Daily retraining as new sales data arrives.